Ice dam risk in Salem, UT
Ice dams in Salem, UT: how often
14.8 dam days a winter
Moderate risk. On an ordinary house in Salem, conditions for an ice dam come on about 14.8 days in a normal winter, mostly in January and December.
Salem averages 66 inches of snow a year and about 61 days with snow on the ground. Snow that lies that long is what turns a little attic heat into a ridge of ice at the eave. The conditions that make a dam need all three at once: snow, cold at the eave and heat above it.
What your attic does to that number in Salem
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 10.5 | Moderate |
| Typical, some insulation, not air-sealed | 14.8 | Moderate |
| Older or poorly insulated, warm attic | 20.2 | High |
Sealing and insulating a typical attic takes out about 4.3 days a winter here. It does not move the risk band, but it shortens every dam. An older house with a warm attic should expect closer to 20.2 days.
Preventing ice dams on a Salem roof
- Air-seal the attic floor: the gaps around the hatch, light fixtures, plumbing stacks and the top plates of interior walls. This is the fix that removes the cause, and it usually costs less than a season of contractor ice removal.
- Rake the bottom three or four feet of roof after any storm that leaves more than about six inches, from the ground with a roof rake.
Which to spend on first: air sealing or heat cable.
Salem winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 17.3 | 20.0 | 5.6 |
| February | 14.1 | 14.0 | 3.0 |
| March | 6.8 | 3.7 | 0.4 |
| April | 4.2 | 0.7 | 0.0 |
| October | 0.5 | 0.3 | 0.0 |
| November | 7.4 | 5.2 | 0.8 |
| December | 15.7 | 17.2 | 4.9 |
Salem next to nearby towns
Salem ranks 31 of 67 Utah cities here for ice-dam days, behind Ogden at 37.2 days.
- Payson, UT 4 mi, 15.9 days
- Spanish Fork, UT 4 mi, 14.8 days
- Mapleton, UT 7 mi, 14.8 days
- Springville, UT 8 mi, 9.3 days
- Santaquin, UT 9 mi, 15.9 days
Where these numbers come from
NOAA 1991–2020 climate normals from Spanish Fk Pwr House, 3.7 miles from Salem. A dam day is a day with snow on the roof and freezing at the eave while heat or sun melts the snow above it. This describes a normal winter, not this one.